The Mystery on Cobbett's Island

“That’s the way the old salts pronounce it.”
    “Aye, aye, Captain, ‘mains’l it shall be, and what do you call this one, a jib or a jab?” Trixie countered with a twinkle in her eyes.
    “That’s a jib. No problem there,” Peter answered. “It’s a smaller sail that goes in front of the mains’l, and here’s the spinnaker,” he said, pulling part of it out of the bag.
    “Oh, what a lovely color!” said Honey. “Are they always blue like that one?”
    “Oh, no. Cap’s is plain white; some are red or yellow or just about any color you can think of, even stripes. It’s quite a sight to see a lot of Lightnings coining down the bay with their spinnakers up. Now, let’s see,” he continued, turning his attention to the other bags. “Here’s the light weather mains’l with its jib, so nothing’s missing. I don’t get it,” he said slowly as he replaced the sails on their pegs.
    Trixie, in the meantime, had been looking around the room, and just as the others were about to go downstairs, she said, “Look, Peter. I’ve never seen you smoke, but does your father?”
    “No, Dad doesn’t smoke, and I hate the things,” he answered. “Why?”
    “Yes, that’s a funny question, Trix. What’s smoking got to do with sails?” Jim asked.
    “Only this. Look over here a minute. See all those cigarette butts?” she asked, pointing to the corner.
    “By Jove, what do you know!” exclaimed Peter as he knelt down beside Trixie, who was examining them closely.
    “Trixie’s found a clue. Trixie’s found a clue,” chanted Mart.
    “Maybe I have and maybe I haven’t, lame-brain, but I know one thing: There are only two brands here. Whoever smoked this filter kind smoked his right down to the tip, but the regular-brand butts are crushed out before they’re half gone,” she observed as she separated the butts into two piles.
    “There must have been just two people up here, then,” said Brian.
    “Elementary, my dear Watson,” quipped Trixie, “and they must have stayed quite a while, judging from the number of cigarettes they smoked.”
    “Like overnight, maybe?” asked Mart.
    “By Jupiter, you’re right!” cried Peter. “And they probably pulled the sail bags down to sleep on. First I thought it might have been some of the little kids from school who think it’s pretty smart to smoke. They know this place and might have come over to sneak a smoke, but they wouldn’t stay a whole night.”
    “It looks as though someone wanted a real hideaway,” Trixie said thoughtfully. “I wonder who.”
    “I guess we’ll have to put a padlock on the door. We’ve never locked up anything around here before. The only way to get off the island is by ferry, so it doesn’t make a very good place for burglars to operate,” Peter commented. “Abe would have them before they could even buy their ferry tickets. They wouldn’t have a chance.”
    “Couldn’t anyone come and go in his own boat?” Diana asked as they went downstairs.
    “Oh, I suppose they could,” Peter answered, “but it isn’t very likely. The mainland is much easier for a professional thief.”
    “Well, it certainly looks as though someone were prowling around here—someone who had no business to, professional or not,” Trixie said solemnly.
    “It’s a funny coincidence that it should happen just after we found the letter, isn’t it?” Honey commented.
    “I wonder if it is coincidence,” Trixie said, half to herself. “Let’s look through this part of the shed and see if we come up with any leads,” she suggested as she started systematically to examine the room.
    The others joined in, but, despite an intensive search, nothing seemed to be missing or out of place. There was no sign of the chart’s having been hidden there, either. No floorboards showed the slightest sign of having been tampered with, and even though they explored the old fireplace brick by brick, it revealed nothing unusual.
    “Gosh,” exclaimed Trixie, who had stuck her head inside one of the little ovens, “there’s nothing in here but spider webs!” She shook her blond curls, which were covered with dust and soot, and brushed the cobwebs from her face. “I don’t think this is the place Ed meant at all. Oh, I’m so disappointed. Instead of finding the chart, all we came up with is evidence of an intruder whom we don’t really want to be bothered with at all!”
    “Oh, let’s forget it. How about a swim to cool off? Last one in’s a